1. Field of the Invention
This invention relates to disk drive suspensions having increased torsional stiffness, and thus higher torsional frequency, without an increase in vertical stiffness, or that maintain a desired torsional stiffness with a reduction in vertical stiffness. More particularly, the invention provides single side-opposed and selectively engaged cooperating structures on the suspension mount plate and the suspension beam portion, in the vertical plane of the hinge portion, to limit relative beam portion rotation and thus increase torsional stiffness, by blocking passing movement of the structure members while allowing freedom of vertical movement away from each other.
2. Description of the Related Art
In the prior art it has been a given that the desirable increase in suspension torsional stiffness had as a necessary concomitant an undesirable increase in vertical stiffness. This association results from the practice of accomplishing vertical stiffness and torsional stiffness with similar techniques, such as making the mount plate and the load beam as rigid as possible, and making the spring of the hinge portion as wide and short as possible. The use of bracketing limiters to restrict vertical movement in both directions (closing and opening gaps between opposed structures rather than only closing as in the present invention) requires the close and synchronously interfittment of minute parts that adds to construction time and expense, and the wearing under friction of the interfitted parts generates erratic and spurious forces on the suspension and may generate damaging detritus.